Android将mp3转成AAC再混合到视频中

    mediaMuxer = MediaMuxer(mSavedFile!!.absolutePath,  
                        MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4)
        if (mAudioPath != "") {
            encodeAudio(mediaMuxer)
            VideoEncoder(this, mSavedFile!!, 25, mediaMuxer,audioCodec).start()
        } else {
            VideoEncoder(this, mSavedFile!!, 25, mediaMuxer,null).start()
        }

    private fun encodeAudio(mediaMuxer: MediaMuxer) {
        audioCodec = AudioEncoder.newInstance()
        audioCodec.setEncodeType(MediaFormat.MIMETYPE_AUDIO_AAC)
        val file = File("/storage/emulated/0/Download/out1.aac")
        if (!file.exists()) {
            file.createNewFile()
        }

        audioCodec.setMuxer(mediaMuxer)
        audioCodec.setTotalTime(mTotalTime)
        audioCodec.setIOPath(mAudioPath)
        audioCodec.prepare()
        audioCodec.setOnCompleteListener { audioCodec.release() }

        Handler().postDelayed({ audioCodec.startAsync(mAudioPath) }, 1000)

//        AudioCodec.getPCMFromAudio(mAudioPath, mAudioPath+".pcm", object : AudioDecodeListener {
//            override fun decodeOver() {
//                Log.e("xxx","mp3 转成 pcm")
//                AudioCodec.PcmToAudio(mAudioPath+".pcm", mAudioPath+".aac", object : AudioDecodeListener {
//                    override fun decodeOver() {
//                        Log.e("xxx","pcm 转成 aac")
//                        Log.e("xxx", "  音频转换完成  ")
//                    }
//
//                    override fun decodeFail() {}
//                })
//            }
//
//            override fun decodeFail() {}
//        })


    }

import android.media.MediaCodec;
import android.media.MediaCodecInfo;
import android.media.MediaExtractor;
import android.media.MediaFormat;
import android.media.MediaMuxer;
import android.os.Build;
import android.os.Handler;
import android.util.Log;

import androidx.annotation.RequiresApi;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.concurrent.CopyOnWriteArrayList;

public class AudioEncoder {

    private static final String TAG = "AudioCodec";
    private String encodeType;
    private String srcPath;
    private MediaCodec mMp3Decoder;
    private MediaCodec mAacEncoder;
    private MediaExtractor extractor;
    private ByteBuffer[] decodeInputBuffers;
    private ByteBuffer[] decodeOutputBuffers;
    private ByteBuffer[] encodeInputBuffers;
    private ByteBuffer[] encodeOutputBuffers;
    private MediaCodec.BufferInfo decodeBufferInfo;
    private MediaCodec.BufferInfo encodeBufferInfo;
    private FileOutputStream fos;
    private BufferedOutputStream bos;
    private ArrayList chunkPCMDataContainer;//PCM数据块容器
    private OnCompleteListener onCompleteListener;
    private OnProgressListener onProgressListener;
    private long fileTotalSize;
    private long decodeSize;
    private MediaMuxer muxer;
    private int audioTrack;
    private boolean codeOver = false;
    private long mAudioPts = 0;
    private long presentationTimeUs;
    ArrayList tempBufferDataList = new ArrayList();

    private int sampleRate = 44100;
    private int channelCount = 1;

    public void setMuxerStart(boolean muxerStart) {
        this.muxerStart = muxerStart;
    }

    private boolean muxerStart = false;

    public void setTotalTime(int mTotalTime) {
        this.mTotalTime = mTotalTime;
    }

    private int mTotalTime;

    public static AudioEncoder newInstance() {
        return new AudioEncoder();
    }

    /**
     * 设置编码器类型
     *
     * @param encodeType
     */
    public void setEncodeType(String encodeType) {
        this.encodeType = encodeType;
    }

    /**
     * 设置输入输出文件位置
     *
     * @param srcPath
     */
    public void setIOPath(String srcPath) {
        this.srcPath = srcPath;
    }

    public void setMuxer(MediaMuxer muxer) {
        this.muxer = muxer;
    }

    public void setAudioTrack(int audioTrack) {
        this.audioTrack = audioTrack;
    }

    /**
     * 此类已经过封装
     * 调用prepare方法 会初始化Decode 、Encode 、输入输出流 等一些列操作
     */
    public void prepare() {

        if (encodeType == null) {
            throw new IllegalArgumentException("encodeType can't be null");
        }

        if (srcPath == null) {
            throw new IllegalArgumentException("srcPath can't be null");
        }

        chunkPCMDataContainer = new ArrayList<>();

        initMediaDecoder();//解码器



    }

    /**
     * 初始化解码器
     */
    private void initMediaDecoder() {
        try {
            extractor = new MediaExtractor();//此类可分离视频文件的音轨和视频轨道
            extractor.setDataSource(srcPath);//媒体文件的位置
            for (int i = 0; i < extractor.getTrackCount(); i++) {//遍历媒体轨道 此处我们传入的是音频文件，所以也就只有一条轨道
                MediaFormat format = extractor.getTrackFormat(i);
                String mime = format.getString(MediaFormat.KEY_MIME);
                if (mime != null && mime.startsWith("audio")) {//获取音频轨道
//                    format.setInteger(MediaFormat.KEY_MAX_INPUT_SIZE, 200 * 1024);
                    extractor.selectTrack(i);//选择此音频轨道
                    mMp3Decoder = MediaCodec.createDecoderByType(mime);//创建Decode解码器
                    mMp3Decoder.configure(format, null, null, 0);
                    sampleRate = format.getInteger(MediaFormat.KEY_SAMPLE_RATE);
                    channelCount = format.getInteger(MediaFormat.KEY_CHANNEL_COUNT);
                    break;
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }

        if (mMp3Decoder == null) {
            Log.e(TAG, "create mMediaDecoder failed");
            return;
        }
        mMp3Decoder.start();//启动MediaCodec ，等待传入数据
        decodeInputBuffers = mMp3Decoder.getInputBuffers();//MediaCodec在此ByteBuffer[]中获取输入数据
        decodeOutputBuffers = mMp3Decoder.getOutputBuffers();//MediaCodec将解码后的数据放到此ByteBuffer[]中 我们可以直接在这里面得到PCM数据
        decodeBufferInfo = new MediaCodec.BufferInfo();//用于描述解码得到的byte[]数据的相关信息
        showLog("decode buffers:" + decodeInputBuffers.length);


        //拿到音频的sourceSampleRate之后再初始化编码器
        mAacEncoder = initAACMediaEncode();//AAC编码器
        if (mAacEncoder == null) {
            Log.e(TAG, "create mMediaEncoder failed");
            return;
        }
        mAacEncoder.start();
        encodeInputBuffers = mAacEncoder.getInputBuffers();
        encodeOutputBuffers = mAacEncoder.getOutputBuffers();
        encodeBufferInfo = new MediaCodec.BufferInfo();

        new Thread(new EncodeRunnable()).start();

    }


    /**
     * 初始化AAC编码器
     *
     * @return
     */
    private MediaCodec initAACMediaEncode() {
        try {
            MediaFormat encodeFormat = MediaFormat.createAudioFormat(MediaFormat.MIMETYPE_AUDIO_AAC, sampleRate, channelCount);//参数对应-> mime type、采样率、声道数
            encodeFormat.setInteger(MediaFormat.KEY_BIT_RATE, 96000);//比特率
            encodeFormat.setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC);
            encodeFormat.setInteger(MediaFormat.KEY_MAX_INPUT_SIZE, 100 * 1024);
            MediaCodec mediaCodec = MediaCodec.createEncoderByType(MediaFormat.MIMETYPE_AUDIO_AAC);
            mediaCodec.configure(encodeFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
            return mediaCodec;
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }


    /**
     * 开始转码
     * 音频数据{@link #srcPath}先解码成PCM  PCM数据在编码成想要得到的{@link #encodeType}音频格式
     * mp3->PCM->aac
     */
    public void startAsync(String audioPath) {
        showLog("start");

        new Thread(new DecodeRunnable()).start();


//        new Thread(new Runnable() {
//            @Override
//            public void run() {
//                audioToAAC(audioPath, -1, -1);
//            }
//        }).start();

//        final String pcmPath = audioPath + ".pcm";
//        final String aacPath = audioPath + ".aac";
//
//        AudioCodec.getPCMFromAudio(audioPath, pcmPath, new AudioCodec.AudioDecodeListener() {
//            @Override
//            public void decodeOver() {
//                Log.e(TAG, "音频解码完成" + pcmPath);
//                AudioCodec.PcmToAudio(pcmPath, aacPath, new AudioCodec.AudioDecodeListener() {
//                    @Override
//                    public void decodeOver() {
//                        Log.e(TAG, "音频编码完成");
//                    }
//
//                    @Override
//                    public void decodeFail() {
//                        Log.e(TAG, "音频编码失败");
//                    }
//                });
//            }
//
//            @Override
//            public void decodeFail() {
//                Log.e(TAG, "音频解码失败");
//            }
//        });

    }

    //尝试将mp3保存成aac，看能不能正常播放  https://blog.csdn.net/qq_29364417/article/details/87989965
    public String audioToAAC(String audioPath, long audioStartTimeUs, long audioEndTimeUs) {

        long a = System.currentTimeMillis();
        int audioExtractorTrackIndex = -1;
        int audioMuxerTrackIndex = -1;
        int channelCount = 1;
        int sourceSampleRate = 0;
        int bitRate = 0;
        String newAudioAAc = "";
        long sourceDuration = 0;

        try {
            File tempFlie = new File(audioPath);
            String tempName = tempFlie.getName();
            String suffix = tempName.substring(tempName.lastIndexOf(".") + 1);
//             newAudioAAc= tempFlie.getParentFile().getAbsolutePath() + "/" + tempName.replace(suffix, "aac");
            newAudioAAc = audioPath + ".aac";
//            muxer = new MediaMuxer(newAudioAAc, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
            //音频信息获取
            MediaExtractor audioExtractor = new MediaExtractor();
            audioExtractor.setDataSource(audioPath);
            int trackCount = audioExtractor.getTrackCount();

            MediaFormat sourceFormat = null;
            String sourceMimeType = "";
            int timeOutUs = 300;

            for (int i = 0; i < trackCount; i++) {
                sourceFormat = audioExtractor.getTrackFormat(i);
                sourceMimeType = sourceFormat.getString(MediaFormat.KEY_MIME);
                channelCount = sourceFormat.getInteger(MediaFormat.KEY_CHANNEL_COUNT);
                sourceSampleRate = sourceFormat.getInteger(MediaFormat.KEY_SAMPLE_RATE);
                bitRate = sourceFormat.getInteger(MediaFormat.KEY_BIT_RATE);

                Log.e("xxx-sourceSampleRate", sourceSampleRate + "");
                Log.e("xxx-bitRate", bitRate + "");
                sourceDuration = sourceFormat.getLong(MediaFormat.KEY_DURATION);
                if (sourceMimeType.startsWith("audio/")) { //找到音轨
                    audioExtractorTrackIndex = i;
                    break;
                }
            }

            //初始化解码器
            MediaCodec audioDecoder = null;
            audioDecoder = MediaCodec.createDecoderByType(sourceMimeType);
            audioDecoder.configure(sourceFormat, null, null, 0);
            audioDecoder.start();


            //初始化编码
            MediaCodec mEncorder = null;
            mEncorder = MediaCodec.createEncoderByType(MediaFormat.MIMETYPE_AUDIO_AAC);
            MediaFormat format = MediaFormat.createAudioFormat(MediaFormat.MIMETYPE_AUDIO_AAC,  sourceSampleRate, channelCount);
            format.setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC);
            Log.e("xxx-sourceSampleRate", sourceSampleRate + "");
            Log.e("xxx-bitRate", bitRate + "");
            format.setInteger(MediaFormat.KEY_BIT_RATE, 96000);  //重新编码的比特率和原音频一样
            format.setInteger(MediaFormat.KEY_MAX_INPUT_SIZE, 1024 * 1024 * 10);
            mEncorder.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
            mEncorder.start();

            //audioExtractor.selectTrack(audioExtractorTrackIndex);

            encodeInputBuffers = mEncorder.getInputBuffers();
            encodeOutputBuffers = mEncorder.getOutputBuffers();
            encodeBufferInfo = new MediaCodec.BufferInfo();

            MediaCodec.BufferInfo sourceAudioBufferInfo = new MediaCodec.BufferInfo();
            MediaCodec.BufferInfo audioBufferInfo = new MediaCodec.BufferInfo();

            ByteBuffer audioByteBuffer = ByteBuffer.allocate(1024 * 1024 * 10);

            FileOutputStream mFilePcm = new FileOutputStream(audioPath+".pcm");

            FileOutputStream mFileStream = new FileOutputStream(newAudioAAc);

            while (true) {
                int readSampleSize = audioExtractor.readSampleData(audioByteBuffer, 0);
                if (readSampleSize < 0) {
                    audioExtractor.unselectTrack(audioExtractorTrackIndex);
                    break;
                }

                long audioSampleTime = audioExtractor.getSampleTime();

                Log.e("xxx-audioSampleTime",audioSampleTime+"");

                //可以做进度回调
                if (audioStartTimeUs != -1 && audioSampleTime < audioStartTimeUs) {
                    audioExtractor.advance();
                    continue;
                }

                if (audioEndTimeUs != -1 && audioSampleTime > audioEndTimeUs) {
                    break;
                }

                int audioSampleFlags = audioExtractor.getSampleFlags();

                //解码
                int sourceInputBufferIndex = audioDecoder.dequeueInputBuffer(timeOutUs);
                if (sourceInputBufferIndex >= 0) {
                    ByteBuffer sourceInputBuffer = null;
                    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
                        sourceInputBuffer = audioDecoder.getInputBuffer(sourceInputBufferIndex);
                    }
                    sourceInputBuffer.clear();
                    sourceInputBuffer.put(audioByteBuffer);
                    audioDecoder.queueInputBuffer(sourceInputBufferIndex, 0, readSampleSize, audioSampleTime, audioSampleFlags);
                }


                int sourceOutputBufferIndex = audioDecoder.dequeueOutputBuffer(sourceAudioBufferInfo, timeOutUs);
                if (sourceOutputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
                    // 后续输出格式变化
                }
                while (sourceOutputBufferIndex >= 0) {
                    ByteBuffer decoderOutputBuffer = null;
                    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
                        decoderOutputBuffer = audioDecoder.getOutputBuffer(sourceOutputBufferIndex);
                    }

                    //编码
                    int inputBufferIndex = mEncorder.dequeueInputBuffer(timeOutUs);
                    if (inputBufferIndex >= 0) {
                        ByteBuffer inputBuffer = null;
                        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
                            inputBuffer = mEncorder.getInputBuffer(inputBufferIndex);
                        }
                        inputBuffer.clear();
                        inputBuffer.put(decoderOutputBuffer);
                        mEncorder.queueInputBuffer(inputBufferIndex, 0, decoderOutputBuffer.limit(), audioSampleTime, audioSampleFlags);
                    }

                    int outputBufferIndex = mEncorder.dequeueOutputBuffer(audioBufferInfo, timeOutUs);
                    if (outputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
                        // 后续输出格式变化
                    }


                    while (outputBufferIndex >= 0) {

                        ByteBuffer outputBuffer = null;
                        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
                            outputBuffer = mEncorder.getOutputBuffer(outputBufferIndex);
                        }
                        int outBufferSize = outputBuffer.limit() + 7;
                        byte[] aacBytes = new byte[outBufferSize];
                        addADTStoPacket(aacBytes, outBufferSize);
                        outputBuffer.get(aacBytes, 7, outputBuffer.limit());

                        mFileStream.write(aacBytes);

                        mEncorder.releaseOutputBuffer(outputBufferIndex, false);
                        outputBufferIndex = mEncorder.dequeueOutputBuffer(audioBufferInfo, timeOutUs);
                    }

                    audioDecoder.releaseOutputBuffer(sourceOutputBufferIndex, false);
                    sourceOutputBufferIndex = audioDecoder.dequeueOutputBuffer(sourceAudioBufferInfo, timeOutUs);
                }
                audioExtractor.advance();
            }

            //释放资源
            mEncorder.stop();
            mFileStream.flush();
            mFileStream.close();
            long b = System.currentTimeMillis() - a;
            Log.i(TAG, "编码结束==" + b);
        } catch (Exception e) {
            e.printStackTrace();

        }
        return newAudioAAc;
    }


    /**
     * 将PCM数据存入{@link #chunkPCMDataContainer}
     *
     * @param pcmChunk PCM数据块
     */
    private void putPCMData(byte[] pcmChunk) {
        synchronized (AudioEncoder.class) {//记得加锁
            chunkPCMDataContainer.add(pcmChunk);
        }
    }

    /**
     * 在Container中{@link #chunkPCMDataContainer}取出PCM数据
     *
     * @return PCM数据块
     */
    private byte[] getPCMData() {
        synchronized (AudioEncoder.class) {//记得加锁
            showLog("getPCM:" + chunkPCMDataContainer.size());
            if (chunkPCMDataContainer.isEmpty()) {
                return null;
            }

            byte[] pcmChunk = chunkPCMDataContainer.get(0);//每次取出index 0 的数据
            chunkPCMDataContainer.remove(pcmChunk);//取出后将此数据remove掉 既能保证PCM数据块的取出顺序 又能及时释放内存
            return pcmChunk;
        }
    }


    /**
     * 解码{@link #srcPath}音频文件 得到PCM数据块
     *
     * @return 是否解码完所有数据
     */
    private void mp3ToPCM() throws IOException {
        fos = new FileOutputStream( srcPath+".pcm");

        for (int i = 0; i < decodeInputBuffers.length - 1; i++) {
            int inputIndex = mMp3Decoder.dequeueInputBuffer(-1);//获取可用的inputBuffer -1代表一直等待，0表示不等待 建议-1,避免丢帧
            if (inputIndex < 0) {
                codeOver = true;
                return;
            }

            ByteBuffer inputBuffer = decodeInputBuffers[inputIndex];//拿到inputBuffer
            inputBuffer.clear();//清空之前传入inputBuffer内的数据
            int sampleSize = extractor.readSampleData(inputBuffer, 0);//MediaExtractor读取数据到inputBuffer中
            long timestampTemp = extractor.getSampleTime();
            if (sampleSize < 0 || timestampTemp > 1000 * mTotalTime) {//小于0 代表所有数据已读取完成
                codeOver = true;
            } else {
                mMp3Decoder.queueInputBuffer(inputIndex, 0, sampleSize, 0, 0);//通知MediaDecode解码刚刚传入的数据
                extractor.advance();//MediaExtractor移动到下一取样处
                decodeSize += sampleSize;
            }
        }

        //获取解码得到的byte[]数据 参数BufferInfo上面已介绍 10000同样为等待时间 同上-1代表一直等待，0代表不等待。此处单位为微秒
        //此处建议不要填-1 有些时候并没有数据输出，那么他就会一直卡在这 等待
        int outputIndex = mMp3Decoder.dequeueOutputBuffer(decodeBufferInfo, 10000);

//        showLog("decodeOutIndex:" + outputIndex);
        ByteBuffer outputBuffer;
        byte[] chunkPCM;
        while (outputIndex >= 0) {//每次解码完成的数据不一定能一次吐出 所以用while循环，保证解码器吐出所有数据
            outputBuffer = decodeOutputBuffers[outputIndex];//拿到用于存放PCM数据的Buffer
            chunkPCM = new byte[decodeBufferInfo.size];//BufferInfo内定义了此数据块的大小
            outputBuffer.get(chunkPCM);//将Buffer内的数据取出到字节数组中
            outputBuffer.clear();//数据取出后一定记得清空此Buffer MediaCodec是循环使用这些Buffer的，不清空下次会得到同样的数据
            //保存到文件中
            fos.write(chunkPCM);
            fos.flush();
            putPCMData(chunkPCM);//自己定义的方法，供编码器所在的线程获取数据,下面会贴出代码
            mMp3Decoder.releaseOutputBuffer(outputIndex, false);//此操作一定要做，不然MediaCodec用完所有的Buffer后 将不能向外输出数据
            outputIndex = mMp3Decoder.dequeueOutputBuffer(decodeBufferInfo, 10000);//再次获取数据，如果没有数据输出则outputIndex=-1 循环结束
        }

        fos.close();

    }

    /**
     * 编码PCM数据 得到{@link #encodeType}格式的音频文件，并保存到{@link }
     */
    @RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)
    private void pcmToAac() {

        int inputIndex;
        ByteBuffer inputBuffer;
        int outputIndex;
        ByteBuffer outputBuffer;
        byte[] chunkAudio;
        int outBitSize;
        int outPacketSize;
        byte[] chunkPCM;


//        showLog("doEncode");
        for (int i = 0; i < encodeInputBuffers.length - 1; i++) {
            chunkPCM = getPCMData();//获取解码器所在线程输出的数据 代码后边会贴上
            if (chunkPCM == null) {
                break;
            }
            inputIndex = mAacEncoder.dequeueInputBuffer(-1);//同解码器
            inputBuffer = encodeInputBuffers[inputIndex];//同解码器
            inputBuffer.clear();//同解码器
            inputBuffer.limit(chunkPCM.length);
            inputBuffer.put(chunkPCM);//PCM数据填充给inputBuffer

            //***************问题在这儿，之前这里写死成441000，导致播放时长变短，音频声音变急促***************/
            presentationTimeUs += (long) (1.0 * chunkPCM.length / ( sampleRate * channelCount * (16 / 8)) * 1000000.0);


            mAacEncoder.queueInputBuffer(inputIndex, 0, chunkPCM.length, presentationTimeUs, 0);//通知编码器 编码
        }

        outputIndex = mAacEncoder.dequeueOutputBuffer(encodeBufferInfo, 10000);//同解码器

        if (outputIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
            audioTrack = muxer.addTrack(mAacEncoder.getOutputFormat());
        } else {
            while (outputIndex >= 0) {//同解码器
                outBitSize = encodeBufferInfo.size;
                outPacketSize = outBitSize + 7;//7为ADTS头部的大小
                outputBuffer = encodeOutputBuffers[outputIndex];//拿到输出Buffer
                outputBuffer.position(encodeBufferInfo.offset);
                outputBuffer.limit(encodeBufferInfo.offset + outBitSize);
                chunkAudio = new byte[outPacketSize];
                addADTStoPacket(chunkAudio, outPacketSize);//添加ADTS 代码后面会贴上
                outputBuffer.get(chunkAudio, 7, outBitSize);//将编码得到的AAC数据 取出到byte[]中 偏移量offset=7 你懂得
                outputBuffer.position(encodeBufferInfo.offset);
                while (!muxerStart) {
                    try {
                        Thread.sleep(100);
                    } catch (Exception e) {

                    }
                }

                //将数据写到混合器的audioTrack轨道中去
                muxer.writeSampleData(audioTrack, outputBuffer, encodeBufferInfo);
                mAacEncoder.releaseOutputBuffer(outputIndex, false);
                outputIndex = mAacEncoder.dequeueOutputBuffer(encodeBufferInfo, 10000);
            }
        }
    }

    public static ByteBuffer clone(ByteBuffer original) {
        ByteBuffer clone = ByteBuffer.allocate(original.capacity());
        original.rewind();//copy from the beginning
        clone.put(original);
        original.rewind();
        clone.flip();
        return clone;
    }

    /**
     * 添加ADTS头
     *
     * @param packet
     * @param packetLen
     */
    private void addADTStoPacket(byte[] packet, int packetLen) {
        int profile = 2; // AAC LC
        int freqIdx = 4; // 44.1KHz
        int chanCfg = 2; // CPE


// fill in ADTS data
        packet[0] = (byte) 0xFF;
        packet[1] = (byte) 0xF9;
        packet[2] = (byte) (((profile - 1) << 6) + (freqIdx << 2) + (chanCfg >> 2));
        packet[3] = (byte) (((chanCfg & 3) << 6) + (packetLen >> 11));
        packet[4] = (byte) ((packetLen & 0x7FF) >> 3);
        packet[5] = (byte) (((packetLen & 7) << 5) + 0x1F);
        packet[6] = (byte) 0xFC;
    }

    /**
     * 释放资源
     */
    public void release() {
        try {
            if (bos != null) {
                bos.flush();
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (bos != null) {
                try {
                    bos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                } finally {
                    bos = null;
                }
            }
        }

        try {
            if (fos != null) {
                fos.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            fos = null;
        }

        if (mAacEncoder != null) {
            mAacEncoder.stop();
            mAacEncoder.release();
            mAacEncoder = null;
        }

        if (mMp3Decoder != null) {
            mMp3Decoder.stop();
            mMp3Decoder.release();
            mMp3Decoder = null;
        }

        if (extractor != null) {
            extractor.release();
            extractor = null;
        }

        if (onCompleteListener != null) {
            onCompleteListener = null;
        }

        if (onProgressListener != null) {
            onProgressListener = null;
        }
        showLog("release");
    }

    /**
     * 解码线程
     */
    private class DecodeRunnable implements Runnable {
        @Override
        public void run() {
            while (!codeOver) {
                try {
                    mp3ToPCM();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    /**
     * 编码线程
     */
    private class EncodeRunnable implements Runnable {

        @Override
        public void run() {
            long t = System.currentTimeMillis();
            while (!codeOver || !chunkPCMDataContainer.isEmpty()) {
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
                    pcmToAac();
                }
            }
            if (onCompleteListener != null) {
                onCompleteListener.completed();
            }
            showLog("size:" + fileTotalSize + " decodeSize:" + decodeSize + "time:" + (System.currentTimeMillis() - t));
        }
    }


    /**
     * 转码完成回调接口
     */
    public interface OnCompleteListener {
        void completed();
    }

    /**
     * 转码进度监听器
     */
    public interface OnProgressListener {
        void progress();
    }

    class TempBufferData {
        public TempBufferData(ByteBuffer byteBuffer, MediaCodec.BufferInfo bufferInfo) {
            this.byteBuffer = byteBuffer;
            this.bufferInfo = bufferInfo;
        }

        ByteBuffer byteBuffer;
        MediaCodec.BufferInfo bufferInfo;
    }
    /**
     * 设置转码完成监听器
     *
     * @param onCompleteListener
     */
    public void setOnCompleteListener(OnCompleteListener onCompleteListener) {
        this.onCompleteListener = onCompleteListener;
    }

    public void setOnProgressListener(OnProgressListener onProgressListener) {
        this.onProgressListener = onProgressListener;
    }

    private void showLog(String msg) {
//        Log.d("AudioCodec", msg);
    }
}

 /**
     * 解码线程
     */
    private class DecodeRunnable implements Runnable {
        @Override
        public void run() {
            while (!codeOver) {
                try {
                    mp3ToPCM();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    /**
     * 编码线程
     */
    private class EncodeRunnable implements Runnable {

        @Override
        public void run() {
            long t = System.currentTimeMillis();
            while (!codeOver || !chunkPCMDataContainer.isEmpty()) {
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
                    pcmToAac();
                }
            }
            if (onCompleteListener != null) {
                onCompleteListener.completed();
            }
            showLog("size:" + fileTotalSize + " decodeSize:" + decodeSize + "time:" + (System.currentTimeMillis() - t));
        }
    }

 /**
     * 解码{@link #srcPath}音频文件 得到PCM数据块
     *
     * @return 是否解码完所有数据
     */
    private void mp3ToPCM() throws IOException {
        fos = new FileOutputStream( srcPath+".pcm");

        for (int i = 0; i < decodeInputBuffers.length - 1; i++) {
            int inputIndex = mMp3Decoder.dequeueInputBuffer(-1);//获取可用的inputBuffer -1代表一直等待，0表示不等待 建议-1,避免丢帧
            if (inputIndex < 0) {
                codeOver = true;
                return;
            }

            ByteBuffer inputBuffer = decodeInputBuffers[inputIndex];//拿到inputBuffer
            inputBuffer.clear();//清空之前传入inputBuffer内的数据
            int sampleSize = extractor.readSampleData(inputBuffer, 0);//MediaExtractor读取数据到inputBuffer中
            long timestampTemp = extractor.getSampleTime();
            if (sampleSize < 0 || timestampTemp > 1000 * mTotalTime) {//小于0 代表所有数据已读取完成
                codeOver = true;
            } else {
                mMp3Decoder.queueInputBuffer(inputIndex, 0, sampleSize, 0, 0);//通知MediaDecode解码刚刚传入的数据
                extractor.advance();//MediaExtractor移动到下一取样处
                decodeSize += sampleSize;
            }
        }

        //获取解码得到的byte[]数据 参数BufferInfo上面已介绍 10000同样为等待时间 同上-1代表一直等待，0代表不等待。此处单位为微秒
        //此处建议不要填-1 有些时候并没有数据输出，那么他就会一直卡在这 等待
        int outputIndex = mMp3Decoder.dequeueOutputBuffer(decodeBufferInfo, 10000);

//        showLog("decodeOutIndex:" + outputIndex);
        ByteBuffer outputBuffer;
        byte[] chunkPCM;
        while (outputIndex >= 0) {//每次解码完成的数据不一定能一次吐出 所以用while循环，保证解码器吐出所有数据
            outputBuffer = decodeOutputBuffers[outputIndex];//拿到用于存放PCM数据的Buffer
            chunkPCM = new byte[decodeBufferInfo.size];//BufferInfo内定义了此数据块的大小
            outputBuffer.get(chunkPCM);//将Buffer内的数据取出到字节数组中
            outputBuffer.clear();//数据取出后一定记得清空此Buffer MediaCodec是循环使用这些Buffer的，不清空下次会得到同样的数据
            //保存到文件中
            fos.write(chunkPCM);
            fos.flush();
            putPCMData(chunkPCM);//自己定义的方法，供编码器所在的线程获取数据,下面会贴出代码
            mMp3Decoder.releaseOutputBuffer(outputIndex, false);//此操作一定要做，不然MediaCodec用完所有的Buffer后 将不能向外输出数据
            outputIndex = mMp3Decoder.dequeueOutputBuffer(decodeBufferInfo, 10000);//再次获取数据，如果没有数据输出则outputIndex=-1 循环结束
        }

        fos.close();

    }

 /**
     * 编码PCM数据 得到{@link #encodeType}格式的音频文件，并保存到{@link }
     */
    @RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)
    private void pcmToAac() {

        int inputIndex;
        ByteBuffer inputBuffer;
        int outputIndex;
        ByteBuffer outputBuffer;
        byte[] chunkAudio;
        int outBitSize;
        int outPacketSize;
        byte[] chunkPCM;


//        showLog("doEncode");
        for (int i = 0; i < encodeInputBuffers.length - 1; i++) {
            chunkPCM = getPCMData();//获取解码器所在线程输出的数据 代码后边会贴上
            if (chunkPCM == null) {
                break;
            }
            inputIndex = mAacEncoder.dequeueInputBuffer(-1);//同解码器
            inputBuffer = encodeInputBuffers[inputIndex];//同解码器
            inputBuffer.clear();//同解码器
            inputBuffer.limit(chunkPCM.length);
            inputBuffer.put(chunkPCM);//PCM数据填充给inputBuffer

            //***************问题在这儿，之前这里写死成441000，导致播放时长变短，音频声音变急促***************/
            presentationTimeUs += (long) (1.0 * chunkPCM.length / ( sampleRate * channelCount * (16 / 8)) * 1000000.0);


            mAacEncoder.queueInputBuffer(inputIndex, 0, chunkPCM.length, presentationTimeUs, 0);//通知编码器 编码
        }

        outputIndex = mAacEncoder.dequeueOutputBuffer(encodeBufferInfo, 10000);//同解码器

        if (outputIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
            audioTrack = muxer.addTrack(mAacEncoder.getOutputFormat());
        } else {
            while (outputIndex >= 0) {//同解码器
                outBitSize = encodeBufferInfo.size;
                outPacketSize = outBitSize + 7;//7为ADTS头部的大小
                outputBuffer = encodeOutputBuffers[outputIndex];//拿到输出Buffer
                outputBuffer.position(encodeBufferInfo.offset);
                outputBuffer.limit(encodeBufferInfo.offset + outBitSize);
                chunkAudio = new byte[outPacketSize];
                addADTStoPacket(chunkAudio, outPacketSize);//添加ADTS 代码后面会贴上
                outputBuffer.get(chunkAudio, 7, outBitSize);//将编码得到的AAC数据 取出到byte[]中 偏移量offset=7 你懂得
                outputBuffer.position(encodeBufferInfo.offset);
                while (!muxerStart) {
                    try {
                        Thread.sleep(100);
                    } catch (Exception e) {

                    }
                }

                //将数据写到混合器的audioTrack轨道中去
                muxer.writeSampleData(audioTrack, outputBuffer, encodeBufferInfo);
                mAacEncoder.releaseOutputBuffer(outputIndex, false);
                outputIndex = mAacEncoder.dequeueOutputBuffer(encodeBufferInfo, 10000);
            }
        }
    }